What You Need To Know About Dealing With Nonunion Fractures

Medically Reviewed By:

Dr. Chaz Fausel, MD

Dr. Chaz Fausel is a Denver-based interventional orthopedics specialist and Regenexx educator, trained at Emory and the Centeno-Schultz Clinic.

Under normal conditions, the body repairs a fracture over time once the bone is properly set and stabilized. A nonunion fracture occurs when a broken bone does not heal as expected, typically within six to nine months. Instead of forming new bone tissue, the fractured ends remain separated, which may lead to discomfort, instability, and difficulty with movement. This condition can impact daily activities, making even simple tasks challenging. Some may find walking or performing basic tasks difficult, which can contribute to emotional strain and a loss of independence. Traditionally, treatment has often involved invasive surgical approaches to restore stability and promote healing.

Why Nonunion Fractures Are Often Referred To As Nonhealing

Nonunion fractures are sometimes known as nonhealing fractures because they do not mend as expected, typically persisting for at least nine months with no visible signs of healing for three consecutive months. Unlike typical fractures that go through a natural recovery process, nonunions occur when bone healing is disrupted, which may be influenced by factors such as reduced blood supply, instability, or underlying health conditions.

When a fracture doesn’t heal properly, it can lead to long-lasting pain and make it hard to use that part of the body. In many cases, doctors need to find and treat the reason the bone isn’t healing. Treatment approaches like specialized interventional orthobiologic procedures may help support the body’s natural healing process without surgery.

Nonunion Vs Malunion

A malunion fracture occurs when a bone heals in a misaligned position. In contrast, a nonunion fracture does not heal as expected, leaving the bone ends unconnected.

In a malunion, the bone may fuse at an incorrect angle, rotate abnormally, or shorten, which can contribute to uneven limb lengths, joint strain, or altered movement patterns. A nonunion may require targeted treatment to support healing, while a malunion may benefit from procedures designed to improve alignment and function.

Causes Of Nonunion Fractures According To Types

Nonunion fractures are classified based on their characteristics and factors affecting healing. Each type influences the bone differently, potentially delaying or disrupting recovery. Common types of nonunion fractures include:

Septic Nonunion

A septic nonunion occurs when an infection affects the healing process of a fracture, potentially leading to inflammation, tissue damage, and reduced blood flow. This can occur after open fractures, surgical complications, or infections that spread from nearby tissues. Symptoms can include prolonged discomfort, swelling, redness, and drainage issues.

Pseudoarthrosis

Pseudoarthrosis is when a nonunion fracture develops a false joint, which may interfere with the bone’s natural healing process. Excessive movement at the fracture site can prevent proper fusion, leading to the formation of a fluid-filled cavity and soft tissue instead of solid bone. This instability may contribute to ongoing discomfort, weakness, and limited mobility.

Hypertrophic Nonunion

A hypertrophic nonunion occurs when excess healing tissue forms, but instability prevents proper fusion. It may result from inadequate fixation (such as loose screws or plates), excessive movement, or insufficient weight-bearing restrictions, potentially leading to ongoing discomfort and limited function.

Atrophic Nonunion

An atrophic nonunion develops when a limited blood supply affects bone healing, leading to minimal or no new bone formation. This type of nonunion may result from severe trauma, infection, or underlying conditions such as diabetes or osteoporosis. The affected bone may become thin and weak, potentially causing ongoing discomfort and instability.

Oligotrophic Nonunion

An oligotrophic nonunion occurs when limited blood flow and minimal biological activity affect fracture healing. Some healing may occur, but inadequate stabilization, poor alignment, or trauma can disrupt fusion. This may result in ongoing discomfort, instability, and reduced mobility.

Key Signs And Symptoms

A nonunion fracture does not heal as expected, which may lead to ongoing discomfort and functional limitations. Identifying the signs early may help guide treatment decisions and reduce the risk of further complications. Common indicators of a nonunion fracture include:

• Persistent pain: The pain from the fracture doesn’t improve over time, and may even get worse with movement or weight-bearing. This happens because the unhealed bones continue to rub against each other, causing inflammation.
• Swelling and tenderness: The area around the fracture remains swollen and tender long after the initial injury. This persistent inflammation is a sign that the body is still trying, and failing, to heal the bone.
• Instability at the fracture site: The injured limb or joint feels wobbly or unstable, and may cause a grinding sensation (crepitus) or abnormal movement when you try to use it. This occurs because the bone fragments are rubbing together
• Limited mobility: Difficulty moving the affected limb or joint. This can be due to pain, instability, or muscle weakness resulting from the unhealed fracture.
• Deformity in the bone: The bone may appear bent or crooked at the fracture site. This could result from a nonunion, where the bones have not aligned and healed properly.
• Chronic inflammation: The body’s prolonged inflammatory response to the unhealed bone can cause chronic pain and swelling. Unlike the initial inflammation, this does not subside and is a sign of an underlying issue.
• Failure to heal is evident on X-rays: X-rays taken months after the injury show a clear gap between the bone fragments or a lack of new bone formation. 
• Weakness in the affected area: The muscles around the fracture site may become weak or atrophy (shrink) due to lack of use, chronic pain, and instability. This can make it difficult to perform daily activities.

Who Is At Risk Of Experiencing Incomplete Bone Healing?

Certain factors may affect the body’s natural healing process, increasing the likelihood of a nonunion fracture. Risk factors include:

• Age and chronic conditions: Aging may reduce bone density and slow healing, while conditions such as diabetes and osteoporosis can weaken bones.
• Nutritional and lifestyle factors: A lack of essential nutrients, smoking, or excessive alcohol use may impair bone healing.
• Use of certain medications: Long-term use of steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), or chemotherapy drugs may interfere with bone formation and the healing process.
• Infections at the fracture site: Infections can disrupt bone repair and increase the risk of septic nonunion.
• History of bone-related conditions: Individuals with previous fractures, metabolic bone diseases, or genetic disorders may have an increased risk of nonunion.
• Activity-related risks: High-impact activities, repeated stress on healing bones, or inadequate fracture stabilization may contribute to incomplete healing.

Diagnosing Nonunion Fractures

Diagnosing a nonunion fracture involves a combination of clinical evaluation and imaging tests to assess bone healing. Physicians in the licensed Regenexx network may use the following methods to confirm the condition and identify contributing factors:

• Physical examination: Assesses discomfort, swelling, tenderness, and instability at the fracture site. Physicians may also assess for abnormal movement or misalignment.
• Laboratory tests: Bloodwork may help to detect infection, nutritional deficiencies, or underlying medical conditions that could impact bone healing.
• X-rays: The first imaging step is to evaluate bone alignment and detect gaps or minimal callus formation, which may indicate incomplete healing.
• CT scans: Provide a more detailed view of the fracture, revealing small gaps or incomplete fusion that may not appear on X-rays.
• MRI: Helps assess soft tissue involvement, blood supply, and possible signs of infection that could affect healing.
• Bone scan: Identifies areas with low metabolic activity, which may indicate a reduced healing response.

Treatment Options For Delayed Fracture Healing

When a fracture does not heal as expected, targeted treatment approaches may help support bone healing and improve function. The most appropriate option depends on the type of nonunion, underlying factors, and overall health. Standard treatment options include:

• Ankle Fusion: Ankle fusion, or arthrodesis, is a surgical procedure that fuses the bones of the ankle joint, limiting motion to support stability in cases of severe arthritis or joint damage. Outcomes vary by individual. Read More About Ankle Fusion.

• SI Joint Fusion: Sacroiliac (SI) joint fusion is a surgical procedure that stabilizes the SI joint by fusing the sacrum and ilium. It may be considered for chronic SI joint pain that has not responded to other treatments. Read More About SI Joint Fusion.
• Spondylolysis Surgery: Surgery for spondylolysis may involve spinal fusion or direct repair of a fractured vertebra to support spinal stability and manage pain. It is typically considered if other treatments do not provide relief. Read More About Spondylolysis Surgery.
• Subtalar Fusion: Subtalar fusion is a surgical procedure that joins the bones of the subtalar joint to support stability and manage discomfort. It is often considered for arthritis, instability, or severe foot deformities. Read More About Subtalar Fusion.

How The Regenexx Approach Supports Bone Regeneration Without Surgery

Since 2005, physicians in the licensed Regenexx network have conducted extensive research,, collected patient outcome data, and refined specialized techniques based on direct patient feedback. This commitment to specialized care may help individuals with nonunion fractures make informed care decisions by exploring non-surgical, less invasive options designed to support recovery.

Patient Results

Physicians in the licensed Regenexx network have performed more than 132,000 procedures worldwide. Regenexx maintains an outcomes database that tracks procedures performed using Regenexx injectates.

Before & After MRI Images

Regenexx has accumulated patient imaging before and after a procedures using Regenexx lab processing to document anatomy change.

Patient Testimonials

Stories of Regenexx provider patients, their treatment results.

Physicians in the licensed Regenexx network may provide a non-surgical alternative for addressing nonunion fractures by utilizing the body’s natural healing processes. Potential benefits of procedures using Regenexx injectates may include:

• May help support bone repair, mobility, and strength.
• May help reduce inflammation and may provide relief at the fracture site.
• Many individuals may experience less downtime, which could allow them to continue daily activities with minimal disruption.
• A potentially reduced recovery time may allow for an earlier return to daily activities.
• May help minimize the risks and extended recovery associated with invasive procedures.
• Some individuals may reduce their reliance on assistive devices during recovery.

Support Your Bone Recovery With Targeted Care

The body typically repairs fractures over time once the bone is set and stabilized. However, in some cases, the healing process slows, resulting in a nonunion fracture. Traditionally, physicians recommend invasive surgery with tissue removal and screws or plates to support bone stability.

Procedures using the Regenexx injectates may support the body’s natural healing process through precise, image-guided injections of healing agents delivered directly to the affected area. This targeted approach may help support bone repair, may help reduce discomfort, and may help improve stability without extensive downtime or surgical intervention.

Individuals experiencing a nonunion fracture may consider a less disruptive treatment option designed to potentially support recovery while fitting into their daily routine.

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Medically Reviewed By:

Dr. Chaz Fausel, MD

Dr. Chaz Fausel is a Denver-based interventional orthopedics specialist and Regenexx educator, trained at Emory and the Centeno-Schultz Clinic.